Knife guard for slicing machines



Feb. 18, 1958 J. D. BRowN KNIFE GUARD FOR sucms MACHINES 6 Sheets-Sheet1 Filed Feb. 24. 1956 ATTORNEW INVENTOR. J w/55 0 BROWN Feb. 18, 1958' vJ. D. BROWN 2,823,718

KNIFE GUARD FOR SLICING MACHINES Filed Feb. 24, 1956 6 Sheets-$heet 2Jag .59 a BRGW/V Feb. 18, 1958 J. D. BROWN KNIFE GUARD FOR sucmc;MACHINES 6 Sheets-Sheet 5 Filed Feb 24, 1956 INVENTOR. JAMES 0. BROWNATTORNEYS Feb. 18, 1958 J. D. BROWN 2,823,713

KNIFE GUARD FOR SLICING MACHINES Filed Feb. 24, 1956 6 Sheets-Sheet 4INVENT OR.

2%; E BQIAIVIES D. BRWN ATTORNEYS Feb. 18, 1958 J. D. BROWN 2,823,718

KNIFE GUARD FOR SLICING MACHINES e sheets-sheet 5 Filed Feb. 24, 1956INVENTOR, "g xlvsEs D. BROWN ATTORNEYS Feb. 18, 1958 J. D. BROWN2,323,713

KNIFE GUARD FOR sucme MACHINES Filed Feb. 24, 1956 s Sheets-Sheet eENVENTOR.

finite KNIFE GUARD FUR SLICING MACHINES James D. Brown, Toledo, Ohio,assignor to Toledo Scale Company, Toledo, Ohio, a corporation of NewJersey This invention relates to slicing machines and particularly toprotective guards for the rotating knives of slicing machines.

The knife of a slicing machine, if proper cutting is to be achieved,must be sharpened to a very high degree. Such sharpness creates certainhazards. Primarily, an operator of such a slicing machine and others whomay come into contact with the machine must be protected from injury bythe knife both during operation of the machine and during the time thatcertain parts of the machine are being removed before cleaning or arebeing replaced after cleaning. secondarily, from the standpoint ofeconomy, the sharp edge of the knife must be protected from being marredby objects which may come into contact with it either during operationof the machine or during the time that certain parts of the machine arebeing removed before cleaning or are being replaced after cleaning.

For these and other reasons, guards of one type or another are generallyprovided to protect the circular knives of slicing machines. Theprovision of such guards creates additional problems, of whichcleanliness is foremost.

In order that a knife guard may be properly cleaned it generally isnecessary to remove it from the slicing machine. Such removal and thereplacement which follows the cleaning must be simple and must beaccomplishable with maximum safety to the operator and without marringthe cutting edge of the knife. Furthermore, the knife guard itselfshould be so constructed that a minimum of cleaning is necessary.

The principal object of this invention is to provide for the circularknife of a slicing machine a knife guard mechanism which may be easilyremoved from or replaced on the machine with both maximum safety to theoperator and without danger of marring the cutting edge of the knife.

Another object of the invention is to provide a knife guard mechanismthe overall design of which is such as to permit easy cleaning.

A further object of the invention is to provide a knife guard mechanismwhich is constructed with a minimum number of parts which may bemanufactured and assembled at low cost.

Still another object of the invention is to provide a knife guardmechanism which permits only the rim of the knife to contact the workmaterial being sliced and permits easy feeding of such material past theknife.

Further objects and advantages will be apparent from the followingdescription in which reference is had to the accompanying drawings.

According to the invention, a rear knife guard is provided for thecircular knife of a slicing machine. The guard has an interrupted frontportion exposing less than one half of the marginal area of the knifeand includes a throat opening toward the interrupted front portion ofthe guard and a flange covering all but the exposed mar- States Patent Iginal portion of the knife. The throat on the guard cooperates with afinger-operable ring cam on the machine by means of which one may shiftthe guard into encom passing relationship with the cutting edge of theknife only when the guard is so placed on the machine that movement ofthe guard toward the knife cannot mar the cutting edge of the knife, andby means of which one may move the guard away from the knife in adirection perpendicular to the plane of the knife for subsequent removalfrom the machine by sliding the guard in its plane until the throat isfree from the cam. Movement of the guard, either toward or away from theknife, is accomplished without danger to the fingers of the operator andwithout danger that the cutting edge of the knife will be marred bystriking it with the guard.

The circular knife may have a marginal area which lies in a plane abouta dished central area. A stationary center plate, which permits only therim of the knife to contact the work material being sliced and whichpermits easy feeding of such material past the knife, is disposed withinthe dished central area of the knife and is substantially coplanar withthe marginal area of the knife to support the pressure of the workmaterial.

In the drawings:

Figure I is an elevational view of a slicing machine embodying theinvention.

Figure II is a fragmentary vertical sectional view taken substantiallyalong the line 11-11 of Figure I.

Figure III is a fragmentary elevational view as seen from a position atthe right of Figure II looking in the direction indicated by the arrowsIIIIII of Figure II.

Figure IV is a detailed elevational view of the knife guard and itssupport showing the knife guard being removed from or being replaced onthe slicing machine by sliding the guard in its plane.

Figure V is a detailed elevational view similar to Figure IV showing theknife guard in operative guarding position on the support therefor.

Figure V1 is an enlarged elevational view of the support for the knifeguard illustrated in Figures IV and V together with a ring cam which isguided in slots in said support.

Figure VII is an elevational view as seen from the line VII-VII ofFigure VI looking in the direction indicated by the arrows.

Figure VIII is an elevational view of the knife guard.

Figure IX is a vertical sectional view taken along the line IX-IX ofFigure VIII. I

Figure X is an enlarged, fragmentary perspective view of those parts ofthe device which are shown in elevation in Figure III.

Referring to the drawings, which disclose a preferred embodiment of theinvention, the slicing machine includes a main base member 1 whichextends across the entire lower portion of the machine, serving as abase and main supporting frame. The base carries cushion members 2 whichare located at the four corners to provide for resiliently supportingthe entire machine in non-slipping engagement above a supportingsurface.

The base is formed with an integral upwardly extending housing 3 (FigureII) at the rear side thereof, and within this housing there is receivedthe drive motor, not shown, the broken away drive shaft of which isshown at 4. The motor thus stands with its drive shaft substantiallyvertical.

A reciprocable commodity carriage 5 carries a substance to be sliced ina work support 6 mounted above the carriage in a plane which issubstantially perpendicular to the plane of a vertical gauge plate 7that is laterally adjustable with respect to the path of movement of thereciprocable carriage 5. Such adjustment of the gauge plate 7 isprovided, as is usual in commodity slicing machines, to vary thethickness of slices. This adjustment is accomplished by rotation of agauge plate knob 8. The work material to be sliced is held between thegauge plate 7 and an ordinary pusher plate 9, the gauge plate beinggrooved as indicated at 16 to allow smooth travel of the work materialover its surface.

Referring to Figure II, the housing 3 supports a hollow bolt 11 having acollar 12 drawn up tight against an eye 13 in the housing by means of anut 14 into which the hollow bolt 11 is screwed. A knife drive member 15is mounted for rotation on ball bearings 16 that are supported by thestationary hollow bolt 11. Fixed on the end of the drive member 15remote from the ball bearings 16 is a circular knife 17 having a cuttingedge or marginal area 18 which lies in a plane about a dished centralarea 19. Power to drive the knife drive member 15 and the circular knife17 fixed thereon is provided by the motor, the broken away drive shaftof which is shown at 4. The motor drive shaft is connected to the drivemember 15 through a worm gear 20 fixed to the drive member which gearmeshes with a drive worm which is not shown but which is secured on themotor drive shaft 4. Suitable sealing elements 21 prevent escape oflubricant outwardly from the bearings 16.

Disposed within the dished central area 19 of the knife 17 andsubstantially coplanar with the marginal area 18 of the knife is astationary center plate 22 to support the pressure of work materialbeing sliced. The center plate 22 is grooved, as indicated at 23, toallow smooth travel of work material past the cutting edge 18 of theknife 17 and covers most of the front surface of the knife so that onlythe rim of the knife contacts the work material. The stationary centerplate 22 is fixed to the housing 3 by means of through bolt 24 which islocated within the hollow bolt 11 and which is end threaded in anextension 25 of the center plate, that fits snugly within an end of thehollow bolt 11, and which is locked by a nut 26. The center plate 22 maybe removed from the housing 3 by removing the nut 26 at the end of thethrough bolt 24. After such removal, the knife 17 and its drive member15 may be removed along with the bearings 16 as a unit by removing thenut 14 at the end of the hollow bolt 11.

The operator and others who may come into contact with the slicingmachine are protected from injury by the knife by means of a rear knifeguard 27. The guard 27 has an interrupted front portion 23 (Figures Iand l1I-V exposing less than one half of the cutting edge 18 of theknife 17 and includes a substantially U-shaped throat 29 opening towardsaid interrupted front portion and a flange 30 covering all but theexposed rear area of the knife. The throat 29 on the rear guard 27cooperates with a finger-operable ring cam 31, surrounding a portion ofa sleeve 32 fixed within the housing 3 by means of a cone-pointed screw33, by means of which one may shift the guard into encompassingrelationship with the cutting edge 18 of the knife only when the guardis so placed on the machine that movement of the guard toward the knifecannot mar the cutting edge 18 of the knife, and by means of which onemay move the guard away from the knife in a direction perpendicular tothe plane of the knife for subsequent re moval from the machine bysliding the guard in its plane until the throat 29 is free from the cam31.

' Cam-guiding slots 34 in the sleeve 32, 180 degrees apart with a risetoward the knife 17 (see Figure VII), are provided as guides forcooperating pins 35 fixed to the ring cam 31. The slots 34 in the sleeveand the pins 35 on the cam 31 guide the cam toward or away from theplane of the knife 17 as indicated by the arrow heads in Figure VII,when finger pressure is applied,fin' one or-the other of the directionsindicated tially U-shaped throat 29 on the guard 27 necessitatingremoval of the guard from the machine by sliding it in its plane untilthe bottom 37a of the throat 29 is free from the groove 37, the bottom37a being in the nature of a tongue which fits closely in the groove 37.When the throat 29 is fully engaged with the circular groove 37 in thecam 31, movement of the cam, by finger pressure on the handle 36, towardthe plane of the knife 17 moves the guard against a rim or abutment 38on the sleeve 32 into encompassing relationship with the cutting edge ofthe knife and movement of the cam away from the plane of the knifewithdraws the guard out of said encompassing relationship. When theguard is in such encompassing relationship, the rim or abutment 38 helpssupport the guard. Movement of the guard, either by cam-movement towardor away from the knife, and its removal or replacement on the machine bysliding it in its plane from or onto the cam respectively isaccomplished without danger to the fingers of the operator and withoutdanger that the cutting edge of the knife will be marred by striking itwith the guard.

As hereinbefore mentioned, one may shift the rear guard 27, by turningthe cam 31, into encompassing relationship with the cutting edge of theknife 17 only when the guard is so placed on the machine that movementof the guard toward the knife cannot mar the cutting edge of the knife.This is an important feature and is illustrated in detail in Figures 1V,V, VIII and IX. Adjacent the throat 29 in the guard there is formed acircular ridge 39 having leading edges or surfaces 40 which by strikingthe abutment 33 on the sleeve 32 limits movement of the guard toward theknife 17 unless the vertical centerline A of the guard coincides withthe vertical centerline B of the sleeve 32. As illustrated in Figure IV,when the guard 27 is being removed or being replaced on the machine bysliding the guard in its plane, the centerlines A and B do not coincideand the leading edges 40 on the ridge 39 on the guard are behind theabutment 38 on the sleeve 32 so that the guard is prevented from beingmoved toward the knife into on compassing relationship therewith. If theguard could be moved toward the knife, as may be done in prior artdevices, when the centerlines A and B do not coincide, the flange 30 onthe guard might strike and mar the cutting edge on the knife 17. Whenthe bottom 37a of the substantially U-shaped throat 29 in the guard 27is fully engaged in the circular groove 37 in the cam 31, the leadingedges or surfaces 457 on the ridge 39 on the guard clear the abutment 38just enough to allow the guard to be moved into operative guardingposition, as illustrated in Figure V. The sectional view, Figure II,'also illustrates the position of the guard in its operative guardingposition with the abutment 38 helping to support the guard. In suchoperative guarding position, flats 41 (Figures IV, V and VIII) at theopen end of the throat 29 in the guard 27 cooperate with a pair of arms42 extending from and integrally formed with the abutment 38 on thesleeve 32 to prevent rotation of the guard about a horizontal axis.

.The arms 42 on the abutment 38 on the sleeve 32 also function topivotally support a slice deflector 43 (Figure III) attached by means'ofa hinge pin 44 in uxtaposition with the exposed rear area 45 of theknife 17. The deflector 43 serves to guide slices of a commoditydownwardly onto the base member 1 behind and below the gauge plate 7.The deflector 43 may be swung away from the knife 17 for cleaningpurposes and swung .toward the knife until a button 46 contacts theknife before the slicing machine is to be used.

When the slicing machine is to be cleaned, the ring cam 31 isrotated byfinger pressure applied to its handle 36 in the right hand direction asviewed in Figure VI.

This causes the ring cam 31 to withdraw the rear guard 27 away from theknife and away from locking engagement with the rim or abutment 38 onthe sleeve 32. The guard 27 is then removed from the machine by slidingit in its plane, as illustrated in Figure IV, until the substantiallyU-shaued throat 29 on the guard is free from the groove 37 in the cam31. The guard 27 is replaced by reversing such steps. Since the guard ismoved into or removed from encompassing relationship with the cuttingedge of the knife by the ring cam 31 and since the engagement of thebottom 37a of the substantially U-shaped throat 29 in the circulargroove 37 in the cam 31 necessitates removal of the guard from themachine by sliding it in its plane until the throat is free from thegroove, the guard may be safely removed and replaced on the machinewithout danger of marring the cutting edge of the knife.

The embodiment of the invention herein shown and described is to beregarded as illustrative only, and it is to be understood that theinvention is susceptible to variation, modification, and change withinthe spirit and scope of the subjoined claims.

Having described the invention, I claim:

1. In a slicing machine, in combination. a housing having a cam-guidingportion, a circular knife that has a marginal area which lies in a planeabout a dished central area and that is mounted for rotation on thehousing, a cam surrounding a part of the housing and cooperating withsaid cam-guiding portion whereby the cam may be moved toward or awayfrom the plane of the knife, a stationary center plate that is carriedby the housing and that is disposed within the dished central area ofthe knife and that is substantially coplanar with the marginal area ofthe knife to support the pressure of work material being sliced, anabutment on the housing between the knife and the cam, and a rear knifeguard that is carried by the cam and that has an interrupted frontportion exposing less than one half of the marginal area of the knifeand that includes a throat opening toward the interrupted front portionof the guard and a flange covering all but the exposed marginal portionof the knife, the throat on the guard being carried by the cam wherebymovement of the cam toward the plane of the knife moves the guardagainst the abutment into encompassing relationship with the cuttingedge of the knife and movement of the cam away from the plane of theknife moves the guard out of such encompassing relationship so that theguard safely may be removed from the machine without danger of marringthe cutting edge of the knife by sliding it in its plane until itsthroat is free from the cam.

2. In a slicing machine, in combination, a housing, a sleeve that isfixed to the housing and that has a camguiding portion, a knife drivemember mounted for rotation within the sleeve, a circular knife that hasa marginal area which lies in a plane about a dished central area andthat is fixed to the knife drive member, a stationary center plate thatis carried by the housing and that is disposed within the dished centralarea of the knife and that is substantially coplanar with the marginalarea of the knife to support the pressure of work material being sliced,a circularly grooved cam surrounding a portion of the sleeve andcooperating with said camguiding portion whereby the cam may be movedtoward or away from the plane of the knife, there being a rim on thesleeve between the knife and the cam, and a rear knife guard that iscarried by the cam and that has an interrupted front portion exposingless than one half of the marginal area of the knife and that includes athroat opening toward the interrupted front portion of the guard and aflange covering all but the exposed marginal portion of the knife, thethroat on the guard engaging 1n the circular groove in the cam wherebymovement of the cam toward the plane of the knife moves the guardagainst the rim of the sleeve into encompassing relationship with thecutting edge of the knife and movement of the cam away from the plane ofthe knife moves the guard out of such encompassing relationship so thatthe guard safely may be removed from the machine without danger ofmarring the cutting edge of the knife by sliding it in its plane untilits throat is free from the cam, said rim on the sleeve helping tosupport the guard in its said encompassing relationship with the knife.

3. In a slicing machine, in combination, a housing, a sleeve that isfixed to the housing and that has at least one cam-guiding slot therein,a knife drive member mounted for rotation within the sleeve, a circularknife that has a marginal area which lies in a plane about a dishedcentral area and that is fixed to the knife drive member, a stationarycenter plate that is carried by the housing and which is disposed withinthe dished central area of the knife and which is substantially coplanarwith the marginal area of the knife to support the pressure of workmaterial being sliced, a circularly grooved cam surrounding a portion ofthe sleeve and cooperating with said cam-guiding slot whereby the cammay be moved toward or away from the plane of the knife, there being arim on the sleeve between the knife and the cam, and a rear knife guardthat is carried by the cam and that has an interrupted front portionexposing less than one half of the marginal area of the knife and thatincludes a substantially U-shaped throat opening toward the interruptedfront portion of the guard and a flange covering all but the exposedmarginal portion of the knife, the bottom of the substantially U-shapedthroat engaging in the circular groove in the cam thereby necessitatingremoval of the guard from the machine by sliding it in its plane untilthe throat is free from the groove, movement of the cam in one directionmoving the guard against the rim on the sleeve into encompassingrelationship with the cutting edge of the knife and movement of the camin the other direction moving the guard out of such encompassingrelationship, said rim on the sleeve both serving to prevent the camfrom moving the guard against the knife to mar its cutting edge if thebottom of the substantially U-shaped throat is not fully engaged in thecircular groove in the cam and to help support the guard when the bottomof the substantially U-shaped throat is fully engaged in the circulargroove and the guard is in its said encompassing relationship with theknife.

4. The combination according to claim 1 wherein a slice deflector isprovided which is pivotally mounted on the abutment and is injuxtaposition with the exposed rear area of the knife.

5. The combination according to claim 2 wherein a slice deflector isprovided which is pivotally mounted on the rim on the sleeve and is injuxtaposition with the exposed rear area of the knife.

6. The combination according to claim 3 wherein a slice deflector isprovided which is pivotally mounted on the rim on the sleeve and is injuxtaposition with the exposed rear area of the knife.

References Cited in the file of this patent UNITED STATES PATENTS1,862,858 Lyon June 14, 1932 2,364,288 Haggerty Dec. 5, 1944 2,573,860Meeker et al. Nov. 6, 1951 2,728,367 Brown Dec. 27, 1955

